Submersible remote operated vehicle tool interchange

ABSTRACT

A tool interchange for a submersible remote operated vehicle (ROV) arm includes a first interchange body that affixes to an ROV arm. A second interchange body is carried by the first interchange body to rotate on a rotation axis. The second interchange body includes a tool mount actuable between gripping an ROV tool to the second interchange body and releasing the ROV tool from the second interchange body. An inductive power coupling part is provided in the tool mount. The inductive power coupling part is presented outwardly in the tool mount opposite the first interchange body, resides on the rotation axis and is fixed with respect to the first interchange body while the second interchange body rotates. The inductive power coupling part is adapted to inductively communicate power with a corresponding inductor power coupling part of the ROV tool when the ROV tool is docked in the tool mount.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a continuation of and claims the benefit of priorityto U.S. patent application Ser. No. 16/376,622, filed Apr. 5, 2019, thecontents of which are incorporated by reference herein

BACKGROUND

In petrochemical exploration and production, many offshore wells are atdepths well beyond the reach of divers. In these instances, asubmersible remote operated vehicle (ROV) is controlled from above thewater's surface to perform some operations in the construction andcontrol of the wells. The ROV has a manipulator arm that can mount toolsfor use in performing these operations. Some manipulator arms have thecapability to remotely release from and attach to tools, so thatdifferent tools can be interchanged while the ROV is subsea.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a submersible remote operated vehicle(ROV) operating subsea;

FIG. 2A is a front, top perspective view of an example tool interchangeconstructed in accordance with the concepts herein, and FIG. 2B is arear, top perspective view of the example tool interchange;

FIG. 3 is a front, top perspective view of an example male mount for usewith the example tool interchange of FIGS. 2A and 2B;

FIG. 4 is a side cross-sectional view of the example tool interchangewith some aspects omitted;

FIG. 5 is a detail side cross-sectional view focused on a hydraulicconnector part of the example tool interchange; and

FIG. 6 is a detail, partial side cross-sectional view of a manifold bodyof the example tool interchange.

Throughout the figures, like reference numbers are used to indicate thelike parts.

DETAILED DESCRIPTION

FIG. 1 shows an example submersible (e.g., a subsea-type) remoteoperated vehicle (ROV) 10. The ROV 10 can be controlled by a humanoperator from a remote location 12, typically above a surface 14 of abody of water, to swim through the water and perform certain operations.The ROV 10 of FIG. 1 includes a manipulator arm 16 with a tool 18attached to its end. In certain instances, the ROV can include one ormore additional arms, such as a grabber or other type of arm, but themanipulator arm 16 is the most dexterous, having multiple pivot androtational joints that enable movement of the arm in multiple degrees offreedom.

The ROV 10 supplies power, e.g., electrical and/or hydraulic power, tothe tool 18 through the manipulator arm 16, enabling the operator toactuate and operate the tool 18. Likewise, the tool 18 and ROV 10communicate data, including output from sensors in the tool 18, controlsignals to actuators in the tool 18, and other data, via the manipulatorarm 16.

FIG. 1 shows the tool 18 as a jaws with two parts that can be operatedto open and close to grasp and hold objects. But, there are a multitudeof different tools that can be used with an ROV, including torque tools,cutters and other tools. The concepts herein encompass a toolinterchange 20 that mounts at the end of the manipulator arm 16, betweenthe manipulator arm 16 and the tool 18, becoming the interface betweenthe arm 16 and the tool 18. The tool interchange 20 enables the ROV 10to change out tools 18 while submersed with no outside assistance. Forexample, the operator can operate the manipulator arm 16 to dock thetool 18 into a tool storage unit. The tool storage unit may be on and/oroff the ROV. The operator can then actuate the tool interchange 20 torelease the tool from the manipulator arm 16, withdraw the manipulatorarm 16 and leave the tool 18 in the tool storage unit. The operator canthen operate the manipulator arm 16 to dock in a different tool 18, andactuate the tool interchange 18 to grip and lock into the new tool 18.Thereafter, the operator can use the different tool 18 in performingoperations.

FIGS. 2A and 2B are front and rear, top perspective views of an exampletool interchange 200 constructed in accordance with the concepts hereinthat can be used as tool interchange 20. The tool interchange 200includes a first interchange body 202 that carries a second interchangebody 204 so that the second interchange body 204 can rotate, relative tothe first interchange body 202, on a rotation axis A-A. Here, therotation axis A-A extends longitudinally through the center of theinterchange tool 200 (the tool 200, here, is generally cylindrical andthe axis A-A is through the center of the cylinder). But, in otherinstances, the axis A-A could be offset from the center of the tool 200.The tool interchange 200 is actuable, via a motor (discussed in moredetail below) to drive the second interchange body 204 to rotate on thefirst interchange body 202. The first interchange body 202 is adapted tophysically affix to the manipulator arm of an ROV, and communicatehydraulically, electrically and/or optically with the systems of theROV, via the manipulator arm. The second interchange body 204 is adaptedto receive and grip and ROV tool, and communicate hydraulically,electrically and/or optically with an ROV tool, such as tool 18.

In FIG. 2B, the first interchange body 202 is shown with an ROVmanipulator arm mount 210 at one end. The ROV manipulator arm mount 210has two outwardly extending flanges 212. The flanges can be affixed,e.g., bolted and/or otherwise, to corresponding flanges on themanipulator arm to mechanically affix the interchange body 202 to themanipulator arm. The ROV manipulator arm mount 210 defines a portion ofthe back face 214 of the first interchange body 202, and includes aplurality of hydraulic ports 216 that correspond to ports on themanipulator arm. The ports 216 seal with the corresponding ports of themanipulator arm (e.g., with o-rings, gaskets and/or otherwise) to allowcommunication of hydraulic fluid between the tool interchange 200 andthe ROV via hydraulic passages and hoses of the manipulator arm. Theback face 214 can additionally include pass-throughs 218 for electricand fiber-optics that allow communication of electrical power,electrical communications and optical communications between the ROV andthe tool interchange 200, via electrical conductors and fiber-optics ofthe manipulator arm. Fewer or additional pass-throughs and/or ports canbe provided. Notably, each of the pass-throughs need not be dedicated toone wire or one fiber-optic, but rather can accommodate bundled cableswith multiple electrical conductors/fiber-optics within the cable.

In FIG. 2A, the second interchange body 204 is shown with a tool mount250 at its end opposite the manipulator arm mount 210. The tool mount250 is actuable between gripping the ROV tool to the second interchangebody 204, so that the manipulator arm can operate the tool, andreleasing the ROV tool from the second interchange body 204, so that thetool can be replaced with a different tool. The tool mount 250 includesan outer perimeter wall 252 that defines, internally, the tool receivingreceptacle 254 within the wall 252.

Referring also to FIG. 3 , the ROV tool is provided with a male mount300 on one end that is designed to be docked in and closely receivedwithin the tool receiving receptacle 254. In certain instances, theperimeter wall 252 is slightly conical or converges towards the rotationaxis A-A to guide the male mount 300 into the receptacle 254 and centerit on the rotation axis A-A. A rotational alignment key 256 protrudesradially inward from the perimeter wall 252, proud of the back wall 258of the tool receiving receptacle 254. The male mount 300 includes acorresponding keyway 302 that receives the rotational alignment key 256as the male mount 300 is docked into the receptacle 254. The key 256 andkeyway 302 mate to rotationally align the male mount 300 with the toolmount 250. In certain instances, the rotational alignment key 256 can benarrower near the top of the perimeter wall 252 and wider near the backwall 258 and the keyway 302 provided with a corresponding shape toincreasingly, more finely rotationally align the male mount 300 with thetool mount 250 as the rotational alignment key 256 is received deeperinto the keyway 302.

The tool mount 250 includes one or more latches 268 (three shown at 120°spacing) pivotally mounted to the perimeter wall 252, and actuablebetween a latched position and an unlatched position. FIG. 2A, and alsoFIG. 4 , shows the latches 268 as being hook shaped, but the latches 268could be another configuration. The figures also show the latches 268 intheir unlatched position, positioned outward, out of the interior of thetool receiving receptacle 254. In response to a signal communicated bythe ROV to the interchange tool 200, the latches 268 are actuated topivot inward toward the rotation axis A-A to the latched position.

Referring briefly to FIG. 4 , the latches 268 are coupled to apiston/cylinder 272 (one per latch 268) that, in response to suppliedhydraulic fluid, actuates the latches 268 between the latched andunlatched positions. The piston/cylinders 272 can be in hydrauliccommunication with the ROV via one or more of the hydraulic ports 216,enabling the ROV to supply hydraulic fluid to the piston/cylinder 272 toactuate the latches 268.

As seen in FIG. 3 , the male mount 300 includes grip pockets 304 aroundits outer perimeter. The grip pockets 304 correspond in number to thelatches 268. When the male mount 300 is docked within the tool receivingreceptacle 254, the latches 268 reside around the outer perimeter of themale mount 300. Moreover, when the male mount 300 is docked within thetool receiving receptacle 254 and rotationally aligned by the key 256and keyway 302, the grip pockets 304 correspond in position to thelatches 268. When the latches 268 are pivoted inwards to the latchedposition, they enter the corresponding grip pockets 304 and clamp themale mount 300 in the docked position, fully received within the toolreceiving receptacle 254. In this position, the end wall 306 of the malemount 300 abuts the back wall 258 of the tool receiving receptacle 254.When the latches 268 are pivoted outwards to the unlatched position,they release from within the corresponding grip pockets 304 and allowthe male mount 300 to be withdrawn from the tool receiving receptacle254. Notably, in certain instances, the latches 268 and correspondinggrip pockets 304 positioned around the perimeter of the tool interchange200 enables a more axially compact assembly of the tool interchange 200and male mount 300 than latches and pockets inboard. This is because theoutboard latches 268 and grip pockets 304 allow other aspects of theinterface to be nested inboard at the same axial position as the latches268 and grip pockets 304.

Referring specifically to FIG. 2A, the back wall 258 of the tool mount250 includes an inductive power coupling part 260 and a fiber-opticcoupling part 262. The inductive power coupling part 260 and fiber-opticcoupling part 262 are both presented outwardly in the tool mount 250, ina direction opposite from the first interchange body 202, so that whenthe male mount 300 is docked in the tool receiving receptacle 254, theinductive power coupling part 260 and fiber-optic coupling part 262 facethe male mount 300. The inductive power coupling part 260 has agenerally planar surface and, in FIG. 2A, is shown as being circular inshape (but it could be other shapes). Both the inductive power couplingpart 260 and fiber-optic coupling part 262 are centered on the rotationaxis A-A and are fixed with respect to the first interchange body 202,so that when the second interchange body 204 rotates the inductive powercoupling part 260 and fiber-optic coupling part 262 remain stationary.

Referring also to FIG. 3 , the end wall 306 of the male mount 300includes a corresponding inductive power coupling part 308 and acorresponding fiber-optic coupling part 310. The corresponding inductivepower coupling part 308 is positioned so that when the male mount 300 isdocked in the tool receiving receptacle 254 of the tool mount 250, thecorresponding inductive power coupling part 308 is adjacent, but spacedapart from (e.g., not touching) the inductive power coupling part 260 ofthe tool mount 250. Likewise, the corresponding fiber-optic couplingpart 310 is positioned so that when the male mount 300 is docked in thetool receiving receptacle 254, the corresponding fiber-optic couplingpart 310 is adjacent, but spaced apart from (e.g., not touching) thefiber-optic coupling part 262 of the tool mount 250. Thus, when thesecond interchange body 204 is rotated on the rotation axis A-A, thecoupling parts 260, 308, 262, 310 do not contact and wear on each other.

The inductive power coupling part 260 is configured to induce power inthe corresponding inductive power coupling part 308 when contacting oreven across an intervening gap to supply power to the tool attached tothe male mount 300. Such an inductive power coupling is not dependentupon contact for efficient transfer of power, and is thus lesssusceptible to debris which may float in between the coupling parts 260,308. Also, such non-contact inductive and fiber-optic couplings can beless complex, with fewer parts to fail and take up less space within theinterchange tool 200 than typical contact-type slip couplings. Theresulting tool interchange can be more compact, which improves dexterityof the ROV with the tool. The inductive power coupling part 260 has alarge area, shown in FIG. 2A as having a diameter approximately half thediameter of the back wall 258 to facilitate high power transfer. Incertain instances, the inductive power coupling is a resonant inductivecoupling, with one or both parts including a resonant circuit. Theinductive power coupling part 260 and corresponding inductive powercoupling part 308 can be sized as needed to efficiently communicate theamount of power needed to operate the tool. Moreover, in certaininstances, the inductive power coupling can provide increased powertransmission to the ROV tool over other types of connectors orcouplings, enabling higher power consumers to be utilized in the ROVtool such as electro hydraulic valves (solenoids, proportional, servo),lights and electric motors as opposed to simply low power sensors.

The fiber-optic coupling part 262 is configured to communicate data(e.g., signals) with the corresponding fiber-optic coupling part 310across the intervening gap to allow the ROV to communicate with the toolattached to the male mount 300. The fiber-optic coupling, for example,allows the ROV access to sensors in the tool, as well as enable otherdata exchange between the tool and ROV.

Referring back to FIG. 2A, the back wall 258 of the tool mount 250includes one or more hydraulic connector parts 264 (five shown). Thehydraulic connector parts 264 are presented outwardly in the tool mount250, in a direction opposite from the first interchange body 202, sothat when the male mount 300 is docked in the tool receiving receptacle254, the hydraulic connector parts 264 face the male mount 300. Thehydraulic connector parts 264 are positioned radially outboard of theinductive power coupling part 260. Referring also to FIG. 3 , the endwall 306 of the male mount 300 includes corresponding hydraulicconnector parts 312, which may correspond in number to the hydraulicconnector parts 264. When the male mount 300 is docked in the toolreceiving receptacle 254, the corresponding hydraulic connector parts312 also correspond in position to the hydraulic connector parts 264.The hydraulic connector parts 264 are spring biased to protrude outwardfrom the back wall 258 and to compress inward, driven by thecorresponding hydraulic connector parts 312, as the male mount 300 movesinto a fully docked position. Thereafter, because of the key 256 beingmated in the keyway 302 of the male mount 300 and because of theclamping force of the latches 268, when the second interchange body 204rotates relative to the first interchange body 202, the male mount (andthus tool) rotate with the second interchange body. The mated hydraulicconnector parts 264, 312 thus move in unison and remain connected.

The details of the hydraulic connector part 264 can be better seen inFIG. 5 . The hydraulic connector part 264 includes an outer housing 502telescopically received in a bore 504 in the second interchange body204. A spring 506 resides between a shoulder 516 and a lower end of thehousing 502, biasing the housing outward from the back wall 258 of thetool receiving receptacle 254. When the corresponding hydraulicconnector part 312 moves against the housing 502, it compresses thespring 506 and pushes the housing into the bore 504. The spring 506maintains pressure between the hydraulic connector part 264 and thecorresponding hydraulic connector part 312 facilitating a robusthydraulic seal between the components. The outlet end of the housing 502includes an aperture 508 plugged by a poppet valve 510 with a poppetvalve seal on its end. A second spring 512 resides between the shoulder514 in the interior of the housing 502 and the poppet valve 510, biasingthe poppet valve 510 into sealing engagement with the interior of theaperture 508. When the corresponding hydraulic connector part 312contacts the hydraulic connector part 264, it pushes the poppet valve510 away from the aperture 508 allowing flow through the aperture 508and between the hydraulic connector parts 312, 264.

Referring back to FIG. 4 , the electrical conductors 266, e.g., wires,and fiber-optic line 270 that supply the inductive coupling part 260 andthe fiber-optic coupling part 262 reside in a central housing 274 fixedto the first interchange body 202. The central housing 274 is centeredon the axis A-A through the second interchange body 204. The centralhousing 274 carries the inductive coupling part 260 and fiber-opticcoupling part 262, supporting these couplings in position at the backwall 258 of the tool receiving receptacle 254. The second interchangebody 204 defines an internal cavity 276 that receives the centralhousing 274, and the second interchange body 204 is carried by the firstinterchange body 202 to rotate around the central housing 274. Althoughomitted from FIG. 4 to show other features of the interchange, a motor(e.g., electric, hydraulic and/or other) can be positioned between thefirst interchange body 202 and the second interchange body 204 toeffectuate rotation of the second interchange body 204 relative to thefirst interchange body 202. The pass through 218 for the electricalconductors and fiber-optic lines connects to an end of the centralhousing 274 through a passage 278 in the first interchange body 202, sothat the electrical conductors 266 and fiber-optic line 270 can beconnected to the inductive coupling part 260 and the fiber-opticcoupling part 262.

The hydraulic ports 216 connect through hydraulic passages 280 in thefirst interchange body 202 to an annular manifold body 282 affixed tothe first interchange body 202. The annular manifold body 282 isgenerally cylindrical, with cylindrical outer and inner surfaces. Theannular manifold body 282 is received in an annular void defined in thesecond interchange body 204, outboard of the cavity 276 that receivesthe central housing 274. In FIG. 4 , the second interchange body 204 isconstructed in multiple parts, including an inner housing 286 that isaffixed to an outer portion 288 of the second interchange body 204 anddefines the cavity 276 that receives the central housing 274. In otherinstances, the second interchange body 204 can have fewer or more parts.

The inner housing 286 carries a number of seals 290 on its outer surfacethat abut with and seal to the inner surface of the annular manifoldbody 282 defining a number of sealed annular passages 292 that arefluidically isolated from one another. In FIG. 4 , there are threesealed annular passages 292 around the inside of the annular manifoldbody 282, but in other instances, there could be fewer or more passages.The outer portion 288 of the second interchange body 204 also carries anumber of seals 290 on its inner surface that abut with and seal to theouter surface of the annular manifold body 282. These seals 290 alsodefine a number of sealed annular passages 292 that are isolated fromone another. In FIG. 4 , there are four sealed annular passages 292around the outside of the annular manifold body 282, but again, in otherinstances, there could be fewer or more passages.

Referring to FIG. 6 , the end of the annular manifold body 282 thatabuts the first interchange body 202 includes hydraulic endwall ports294 that correspond in number and position to the hydraulic passages 280in the first interchange body 202, so that they seal up to andfluidically communicate with the hydraulic passages 280 when the annularmanifold body 282 is affixed to the first interchange body 202. Thehydraulic ports 294 communicate fluid with internal passages 296 withinthe annular manifold body 282, which in turn, communicate fluid withselected ones of a number of sidewall ports 298 into the annularpassages 292. As seen in FIG. 4 , the second interchange body 204includes a network of hydraulic passages 206 that fluidicallycommunicate with the annular passages 292. The hydraulic passages 206communicate hydraulic fluid with various aspects of the tool interchange200, including the hydraulic connector parts 264, the piston/cylinder272, and/or other aspects of the tool interchange 200. Thus, internalpassages 296 of the annular manifold body 282 effectuate specifiedfluidic connections between the ports 216 in the first interchange body202 and the various aspects of the tool interchange 200 so that the ROVcan communicate fluid with these aspects to control the tool interchange200 and communicate fluid with a docked ROV tool.

By way of example, the two passages 206 visible in FIG. 5 can bedesignated latch control passages, because they connect to opposingsides of the piston/cylinder 272. Each connects to a different one ofthe isolated annular passages 292, enabling the ROV to apply hydraulicpressure to corresponding ports 216 in the first interchange body 202 toindependently and selectively pressurize these passages. The by applyingpressure to the corresponding port 216, the ROV can actuate the latches268 between a latched and unlatched position.

Because the annular manifold body 282 is fixed to the first interchangebody 202, the second interchange body 204 rotates around the annularmanifold body 282 as the second interchange body 204 is rotated on therotation axis A-A. Because of their annular arrangement, the seals 290remain in sealing contact with the annular manifold body 282 andmaintain the annular passages 292 isolated from one another. Also,because they passages 292 are annular, they continue to providecommunication between the sidewall ports 298 in the annular manifoldbody 282 and the passages 206 of the second interchange body 204. Thus,the fluidic connections between the ports 216 in the first interchangebody 202 and the various aspects of the tool interchange 200 aremaintained while the second interchange body 204 rotates and regardlessof its angular orientation. In other words, the ROV can communicatefluid with these aspects to control the tool interchange 200 andcommunicate fluid with a docked ROV tool while the second interchangebody 204 is being rotated and regardless of its angular orientation. Thearrangement eliminates the need for connecting hoses between the bodies202, 204 that may twist up and limit the rotation of the secondinterchange body 204.

In operation, with reference to FIGS. 2A, 2B and 3 , the male mount 300of an ROV tool is received into the tool mount 250 of the toolinterchange 200 while the tool interchange 200 is coupled to an ROVmanipulator arm. If the male mount 300 is angularly misaligned with thetool mount 250, the second interchange body 204 can be rotated until thekey 256 of the tool mount 250 drops into the key way 302 of the malemount 300 allowing the male mount 302 to descent to the fully dockedposition or close to the fully docked position within the tool receivingreceptacle 254. The ROV operator then actuates the ROV to supplyhydraulic pressure on the hydraulic channel corresponding to thepiston/cylinders 272 to actuate the latches 268 from an unlatchedposition to a latched position which will draw the male mount to thefully docked position. In the latched position, the latches 268 grip theROV tool to the tool mount 250. Thereafter, the tool interchange 200 caninductively communicate power with the ROV tool via the inductivecoupling 260, 308, communicate data (e.g., signals) with the ROV toolvia the fiber-optic coupling 262, 310, and communicate hydraulicallywith the ROV tool via the hydraulic connectors 264, 312. These variousforms of communication can occur while the second interchange portion204 is being rotated relative to the first interchange portion 202, forexample during manipulation and operation of the tool, and regardless ofthe angular orientation of the second interchange portion 204 relativeto the first interchange portion.

While a number if implementations have been described, it should beappreciated that the concepts herein are not limited to thoseimplementations. Rather, other changes, substitutions, and alterationsare also possible without departing from this disclosure.

We claim:
 1. A tool interchange for a submersible remote operatedvehicle (ROV) arm, the tool interchange comprising: a tool mountactuable between gripping an ROV tool and releasing the ROV tool, thetool mount including a perimeter wall that defines a tool receivingreceptacle, and; a power coupling part in the tool mount, the powercoupling part adapted to communicate power with a corresponding powercoupling part of the ROV tool when the ROV tool is docked in the toolmount, wherein the power coupling part is fixed so as not to rotatablymove while the tool mount is rotatable about a rotation axis, andwherein the ROV tool is manipulable while the tool mount is gripping theROV tool; wherein the power coupling part includes an inductive powercoupling part; where the corresponding power coupling part of the ROVtool includes an ROV tool inductive power coupling part, and wherein theinductive power coupling part of the tool mount includes a resonantinductive power coupling part adapted to inductively communicate powerwith the ROV tool inductive power coupling part while the inductivepower coupling part of the tool mount is spaced from the ROV toolinductive power coupling part.
 2. The tool interchange of claim 1,comprising a fiber-optic coupling part located in the tool mount.
 3. Thetool interchange of claim 2, wherein the fiber-optic coupling part islocated on the rotation axis.
 4. The tool interchange of claim 1,comprises a first interchange body that affixes to the ROV arm and asecond interchange body carried by the first interchange body to rotateon a rotation axis.
 5. The tool interchange of claim 4, wherein afiber-optic coupling part is fixed with respect to the first interchangebody, the fiber-optic coupling part adapted to communicate with acorresponding fiber-optic coupling part of the ROV tool when the ROVtool is docked in the tool mount.
 6. The tool interchange of claim 2,where the fiber-optic coupling part is adapted to communicate with thecorresponding fiber-optic coupling part of the ROV tool when the partsare spaced apart.
 7. The tool interchange of claim 2, comprising acentral housing fixed to the first interchange body and extending alongthe rotation axis, the central housing comprising the power couplingpart and the fiber-optic coupling part; and where the second interchangebody is carried to rotate around the central housing.
 8. A toolinterchange for a submersible remote operated vehicle (ROV) arm, thetool interchange comprising: a tool mount actuable between gripping anROV tool and releasing the ROV tool, the tool mount including aperimeter wall that defines a tool receiving receptacle; a powercoupling part in the tool mount, the power coupling part adapted tocommunicate power with a corresponding power coupling part of the ROVtool when the ROV tool is docked in the tool mount, wherein the powercoupling part is fixed so as not to rotatably move while the tool mountis rotatable about a rotation axis, and wherein the ROV tool ismanipulable while the tool mount is gripping the ROV tool; where thetool mount comprises a latch on the perimeter actuatable between alatched position, the latch in the latched position when the tool mountis gripping the ROV tool, and an unlatched position, the latch pivotedoutward to release the ROV tool from a second interchange body when inthe unlatched position; and the tool interchange comprising a toolrotational alignment key adjacent the perimeter wall and extending intothe tool receiving receptacle.
 9. The tool interchange of claim 8,comprising a plurality of hydraulic connector parts on the secondinterchange body within the tool receiving receptacle and radiallyoutboard of the inductive power coupling part, the hydraulic connectorparts adapted to communicate hydraulic pressure with correspondinghydraulic connector parts of the ROV tool and carried to rotate with thesecond interchange body.
 10. A tool interchange for a submersible remoteoperated vehicle (ROV) arm, the tool interchange comprising: a toolmount actuable between gripping an ROV tool and releasing the ROV tool,the tool mount including a perimeter wall that defines a tool receivingreceptacle; a power coupling part in the tool mount, the power couplingpart adapted to communicate power with a corresponding power couplingpart of the ROV tool when the ROV tool is docked in the tool mount,wherein the power coupling part is fixed so as not to rotatably movewhile the tool mount is rotatable about a rotation axis, and wherein theROV tool is manipulable while the tool mount is gripping the ROV tool; afiber-optic coupling part located in the tool mount; a central housingfixed to the first interchange body and extending along the rotationaxis, the central housing comprising the power coupling part and thefiber-optic coupling part; and where the second interchange body iscarried to rotate around the central housing; and where the hydraulicconnector parts are each spring biased to protrude outward of a surfaceof the tool receiving receptacle and to compress in mating engagementwith the corresponding hydraulic connector parts on the ROV tool.
 11. Atool interchange for a submersible remote operated vehicle (ROV) arm,the tool interchange comprising: a tool mount actuable between grippingan ROV tool and releasing the ROV tool, the tool mount including aperimeter wall that defines a tool receiving receptacle; a powercoupling part in the tool mount, the power coupling part adapted tocommunicate power with a corresponding power coupling part of the ROVtool when the ROV tool is docked in the tool mount, wherein the powercoupling part is fixed so as not to rotatably move while the tool mountis rotatable about a rotation axis, and wherein the ROV tool ismanipulable while the tool mount is gripping the ROV tool; a fiber-opticcoupling part located in the tool mount; a central housing fixed to thefirst interchange body and extending along the rotation axis, thecentral housing comprising the power coupling part and the fiber-opticcoupling part; and where the second interchange body is carried torotate around the central housing; and the tool interchange comprisingan annular manifold fixed with respect to the first interchange body andextending into the second interchange body, the annular manifoldcomprising: a manifold body with a cylindrical outer surface; a firsthydraulic passage in the manifold body, the first hydraulic passage influid communication with a first corresponding hydraulic passage of thefirst interchange body and comprising a first sidewall port on thecylindrical outer surface; a second hydraulic passage in the manifoldbody, the second hydraulic passage in fluid communication with a secondcorresponding hydraulic passage of the first interchange body andcomprising a second sidewall port on the cylindrical outer surface; anda seal on the manifold body between the first hydraulic passage and thesecond hydraulic passage, the seal sealing between the cylindrical outersurface and the second interchange body.
 12. A tool interchange for asubmersible remote operated vehicle (ROV) arm, the tool interchangecomprising: a tool mount actuable between gripping an ROV tool andreleasing the ROV tool, the tool mount including a perimeter wall thatdefines a tool receiving receptacle; a power coupling part in the toolmount, the power coupling part adapted to communicate power with acorresponding power coupling part of the ROV tool when the ROV tool isdocked in the tool mount, wherein the power coupling part is fixed so asnot to rotatably move while the tool mount is rotatable about a rotationaxis, and wherein the ROV tool is manipulable while the tool mount isgripping the ROV tool; where the tool mount comprises a latch on theperimeter actuatable between a latched position, the latch in thelatched position when the tool mount is gripping the ROV tool, and anunlatched position, the latch pivoted outward to release the ROV toolfrom a second interchange body when in the unlatched position; and thetool interchange comprising a latch control hydraulic passage in thesecond interchange body that is in fluid communication with the firsthydraulic passage and isolated from the second hydraulic passage andwhere the second hydraulic passage is in fluid communication with ahydraulic connector part adapted to communicate hydraulic pressure witha corresponding hydraulic connector part of the ROV tool.
 13. A method,comprising: receiving an ROV tool at least partially within a toolreceptacle of a tool mount of a tool interchange coupled to an ROV arm;gripping the ROV tool at the tool interchange in response to a signal;and inductively communicating power between the ROV and the ROV toolthrough an inductive coupling, the inductive coupling rotatably fixedsuch that the inductive power coupling part does not rotatably moverelative a rotation axis of the tool interchange during gripping of theROV tool; and communicating signals between the ROV and the ROV toolthrough a fiber-optic coupling residing on the rotation axis; whereinductively communicating power comprises inductively communicatingpower across a gap between a first inductive coupling part of the toolinterchange and a second inductive coupling part of the ROV tool. 14.The method of claim 13, where gripping the ROV tool comprises movinglatches that are on the outermost perimeter of the tool interchange froman unlatched position inward to a latched position to grip the ROV tool,the method further comprising releasing the ROV tool, where releasingthe ROV tool comprises moving the latches from the latched positionoutward to an unlatched position.
 15. The tool interchange of claim 14,wherein the tool interchange includes a first interchange body thataffixes to the ROV arm and a second interchange body carried by thefirst interchange body to rotate on the rotation axis.